Integrative Physiological Approaches to Thermoregulatory and Thermosensory Biology

温度调节和热感觉生物学的综合生理学方法

• 批准号: RGPIN-2014-05814
• 负责人: Tattersall, Glenn
• 金额: $ 2.91万
• 依托单位: Brock University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=567406
• 关键词: Integrative; Physiological; Approaches; Thermoregulatory; Thermosensory

As a complex biological trait, animal thermal physiology involves the co-evolution of thermal sensation along with biochemical mechanisms of thermal tolerance. Therefore, animals with different body temperatures should show functional differences in the properties of their molecular thermal sensors that coincide with their optimal temperatures. Understanding the thermal physiology of animals is important from a basic and an applied perspective, particularly as climate change models predict steep changes in environmental temperatures. The volitional thermal choices made by animals will play an important role in mitigating the effects of climate warming, especially if temperatures rise at rates faster than physiological tolerances evolve. Therefore, understanding how organisms regulate their body temperature is important since it illustrates their potential to respond to change in the environment. Indeed, recent studies suggest that species with narrow behavioural niches will be more adversely affected by rising temperatures; conversely, species with narrow thermal optimalities will be forced to compensate behaviourally in the future in order to achieve body temperatures within this narrow range. Traditionally, much thermal biology research focuses on the effects that temperature pose on animals rather than the influence animals have on their own temperature. My laboratory focuses on both the conserved as well as the unique mechanisms available to animals that bestow their abilities to modify and regulate their internal body temperature; these include behavioural, physiological, molecular and biochemical. In order to control body temperature, animals require: an ability to sense temperature, a central organizer to process and direct thermoeffector responses, and an array of effectors to bring out changes in temperature. This diffusively organized control system is phylogenetically ancient and exhibits remarkable variability. Yet certain elements seem relatively preserved, namely the sensation of temperature, which appears to derive from molecular thermosensors sharing similar biochemical properties and the integration of these signals in the brain, which seem to share dual set-point like behaviour. Below the brain is where the thermoregulatory systems diverge, with various anatomical, biochemical, physiological and behavioural adaptations responsible for effecting thermally relevant changes. The sensory system is the first filtering mechanism available to animals in responding to their thermal environment. Recent advances have used genetic, molecular and in vitro approaches to understand an ever burgeoning array of putative temperature sensors, yet definitive information that these sensors are necessary and sufficient to produce real-life thermosensory behaviours in vivo are lacking. Knock-out models show some promise in this regard, yet suffer from the usual problems in that pleiotropic effects of genes are masked or the ability of the organism to compensate with other pathways is assumed to be absent. Over the next five years we will: 1) study the regulatory pathways (behavioural and physiological) that control Tb in animals by examining the physiological relevance of altered thermoregulatory states (e.g. hypoxia, hydrogen sulfide); 2) examine the mechanisms of warm and cold thermosensation and establish their roles in thermoregulatory behaviours through a comparative analysis of animals with different thermoregulatory preferences; 3) study the development and plasticity of thermoregulatory "appendages" and the interactions between water conservation and temperature regulation.

动物热生理作为一种复杂的生物学特性，涉及到热感觉的共同进化以及热耐受的生化机制。因此，不同体温的动物应该表现出与其最适温度相一致的分子热传感器特性的功能差异。从基础和应用的角度了解动物的热生理很重要，特别是在气候变化模型预测环境温度急剧变化的情况下。动物自愿做出的热选择将在减轻气候变暖的影响方面发挥重要作用，特别是如果气温上升的速度快于生理耐受性的演变。因此，了解生物体如何调节它们的体温很重要，因为它说明了它们对环境变化做出反应的潜力。事实上，最近的研究表明，具有狭窄行为生态位的物种将受到气温上升的更不利影响；相反，具有狭窄热优化的物种将被迫在未来进行行为补偿，以便在这个狭窄的范围内实现身体温度。传统上，许多热生物学研究侧重于温度对动物的影响，而不是动物对自身温度的影响。我的实验室专注于动物可以利用的保守和独特的机制，这些机制赋予它们改变和调节体内体温的能力；这些机制包括行为、生理、分子和生化。为了控制体温，动物需要：感知温度的能力，处理和指导热效应器反应的中央组织器，以及产生温度变化的一系列效应器。这种分散组织的控制系统在系统进化上是古老的，并表现出显著的变异性。然而，某些元素似乎相对保存了下来，即温度感觉，这似乎来自具有相似生化特性的分子温度传感器，以及这些信号在大脑中的整合，这些信号似乎具有双重设定点类似的行为。大脑下方是体温调节系统的分歧之处，各种解剖、生化、生理和行为适应负责影响与体温相关的变化。感官系统是动物对热环境做出反应时可用的第一种过滤机制。最近的进展是使用遗传、分子和体外方法来理解一系列假设的温度传感器，但缺乏明确的信息，即这些传感器是必要的，并且足以在体内产生真实的温度传感行为。基因敲除模型在这方面显示出了一些希望，但受到了通常的问题的困扰，因为基因的多效性效应被掩盖了，或者生物体用其他途径补偿的能力被认为是缺失的。在接下来的五年里，我们将：1)通过检测改变的体温调节状态(如低氧、硫化氢)的生理学相关性，研究控制动物结核病的调控途径(行为和生理)；2)通过对具有不同体温调节偏好的动物的比较分析，研究冷、暖体温调节的机制，并确定它们在体温调节行为中的作用；3)研究体温调节“附属物”的发育和可塑性，以及水保护和温度调控之间的相互作用。